Math Riddles

Riddle 8

Three Brothers on a Farm

Three brothers live in a farm. They agreed to buy new seeds: Adam and Ben would go and Charlie stayed to protect fields. Ben bought 75 sacks of wheat in the market whereas Adam bought 45 sacks. At home, they split the sacks equally. Charlie had paid 1400 dollars for the wheat. How much dollars did Ben and Adam get of the sum, considering equal split of the sacks?

Riddle 9

The Insurance Salesman

An insurance salesman walk up to house and knocks on the door. A woman answers, and he asks her how many children she has and how old they are. She says I will give you a hint. If you multiply the 3 children’s ages, you get 36. He says this is not enough information. So she gives a him 2 nd hint. If you add up the children’s ages, the sum is the number on the house next door. He goes next door and looks at the house number and says this is still not enough information. So she says she’ll give him one last hint which is that her oldest of the 3 plays piano.

Why would he need to go back to get the last hint after seeing the number on the house next door?

Because the sum of their ages ( the number on the house) is ambiguous and could refer to more than 1 trio of factors.

Answer to Riddle

If you list out the trio of factors that multiply to 36 and their sums, you get.

1 1 36 = 38

1 2 18 = 21

1 3 12 = 16

1 4 9 = 14

6 6 1 = 13

2 2 9 = 13

2 3 6 = 11

3 3 4 = 10

Since the number on the house next door is not enough information there must be more than 1 factor trio that sums up to it, leaving two possibilities: < 6, 6, 1>. <2, 2, 9>. When she says her ‘oldest’ you know it can not be <6,6,1> since she would have two ‘older’ sons not an ‘oldest’.

Riddle 10

This is a famous one. The classic Monty hall riddle!

You are confronted by 3 doors. Behind one of them is a car, behind the two others, you will only see a goat. Now, if you correctly pick the car, you win the car. Otherwise, if you get one of the 2 goats, you don’t get the car.

So, pick any door. It doesn’t matter which one, but we will suppose that you picked door #2, as an example.

Now, after you have picked a door and before finding out what is actually behind it, you are shown a goat behind one of the other doors.(Remember there has to be a goat in 1 of the doors that you have not picked. )

Let’s say you choose door #2, as shown above. For example’s sake, let’s say there’s a goat in door 1. The question and the riddle is. should you switch the door that you picked? In other words, in this example, should you now choose door 3? Or, should you stick with your first choice (door #2)?

There actually is a mathematically correct answer to this riddle: You should indeed change your choice. If you don’t believe me, just try out our free online Monty hall simulation .

Riddle 11

If 9999 = 4, 8888 = 8, 1816 = 6, 1212 = 0, then 1919 =

Look at how many closed areas there are.

9999 has 4 closed areas (the top of the ‘9’)

8888 has 8 closed areas, the top and bottom parts of the 8 and there are no other digits

1816 has 3 closed areas, (top and bottom of 8 and bottom of 6, and it has 2 other digits ( 3*2=6)

1212 has 0 closed areas,(0*4=0)

Riddle 12

An athlete is able to jump FOREVER. However, everytime that she jumps she gets a bit more tired, and every jump goes $$ \frac 1 2 $$ as far as her prior jump. Now, for her very first jump, she goes $$ \frac 1 2 $$ of a foot.

On her second jump, she goes $$ \frac 1 4 $$ of a foot, and so on and so forth. The beginning of her journey is shown in the gif below.

How many jumps does it take for her to travel 1 foot?

She will never get to the 1 foot mark because you keep adding smaller and smaller amounts!

Other Good Riddles

Quick summary of riddle: Zeno of Elea (490-425 BC) is known for creating many paradoxes which were debated by mathematicians for centuries. His riddle involving Achilles, the character from Homer’s Iliad and a tortoise went something like:

The tortoise challenged Achilles to a race and Achilles, full of typical hubris, accepted and even gave the Tortoise a 10 foot head start. Before the race started, the tortoise told Achilles that the reason Achilles would lose is that even though Achilles would be catching up, the tortoise would always be moving ahead. Therefore, Achilles would always be covering a fraction of the distance between the two. Let’s say he covered half of the distance in 1 second (5 feet) and then in the next he covered half of the new distance, the remaining 5 feet plus the Tortoise’s new distance. In the end, the tortoise convinced Achilles that he could not win the race because although he would be getting closer and closer, he would still always be covering smaller and smaller fractions of the total distance between the two. Therefore, Achilles forfeited the race. To read this riddle in a modern narrative form click here .

IQ Test Questions with Answers – Brain Teasers & Puzzles

Last updated on 13 Oct, 2010 by Editor

This IQ test comprise of a collection of puzzles. and the questions in this IQ test are interesting and will involve the reader while solving them. The puzzles are short in length but will force you to exercise your brain and use your logical skills. The puzzles are of a wide range and they vary from simple ones to the more difficult ones.

IQ Test Questions

There are 17 questions to test your IQ. Do not look at the answers found at the end of this document, that would be cheating. Write each of your answers down, it makes a difference. Good Luck for the IQ Test!

1. Two people were walking in opposite directions. Both of them walked 6 miles forward then took right and walked 8 miles. How far is each from starting positions?

a) 14 miles and 14 miles b) 10 miles 10 miles c) 6 miles 6 miles

2. A person has certain number of cows and birds. They have 172 eyes and 344 legs. How many cows and birds does he have?

3. A person has 14 red socks and 14 white socks in a drawer. What is the minimum number of socks that he should take to get a correct pair?

4. When a number is multiplied by 13, it becomes greater to 105 by an amount with which it is lesser to 105 by now. What is the number

5. When asked in an exam how much time is left, the teacher answered that the amount of time left is 1/5 of the time already completed. How much time is left?

6. Two people on cycle are traveling at 10 miles/hour in opposite direction. When they are at a distance of 50 miles, a housefly lands on the first cyclist and then flies to the other at a speed of 16 miles/hour. What is the distance covered by fly?

7. My successor’s father is my father’s son. and I don’t have any brothers or sons. Who is my successor?

a) Nephew b) Niece c) Daughter d) Myself

8. A fast train leaves London for Brighton and at the same time a slow train leaves Brighton for London. The fast train leaves at 80 mph and the slow train travels at 35 mph. When they meet, which is farther from London?

9. A girl, a boy, and a dog start walking down a road. They start at the same time, from the same point, in the same direction. The boy walks at 5 km/h, the girl at 6 km/h. The dog runs from boy to girl and back again with a constant speed of 10 km/h. The dog does not slow down on the turn. How far does the dog travel in 1 hour?

10. A pool has four taps. The first tap takes two days to fill the pool, the second tap three days, the third four days and the last one only 6 hours. How long will it take to fill the pool using all 4 taps at once?

11. This was a burglary in the Silver City jewelry store last Sunday. Three suspects: Robert, Scott, and Tommy were caught and questioned. Each person said, “One of the other two stole it. I did not do it.” Later on the police found out that Tommy was lying and there was only one thief. Who was the thief?

12. James visited an island. There were 2 tribes living on this island. The east tribal people always tell a lie. The west tribal people always tell the truth. James saw a guy passing him. He asked the tour guide to ask that guy where he lives. The tour guide asked the guy and came back with the answer: he lives over west. Did the tour guide tell the truth or tell a lie?

13. I have a horse. Do you know what color it is? Allan said, “I guess it is not black”. Brian said, “It is either brown, or gray”. Charlie said “I know it is brown”. I said, “At least one of you is right and at least one of you is wrong.” What is the color of my horse if the color is one of the above?

14. A lady and a gentleman are sister and brother. We do not know who is older. Someone asked them: Who is older? The sister said: I am older. The brother said: I am younger. At least one of them was lying. Who is older?

15. A six digit number 312132 has two 1’s, two 2’s and two 3’s. This number has a very interesting attribute: 1 digit exists between two 1’s, 2 digits exist between two 2’s and 3 digits exist between two 3’s. Can we add two more 4s to become an eight digit number and still holding the above attributes plus 4 digits exist between two 4s?

16. Suppose 8 monkeys take 8 minutes to eat 8 bananas. (a) How many minutes would it take 3 monkeys to eat 3 bananas? (b) How many monkeys would it take to eat 48 bananas in 48 minutes?

17. A group of friends went to a hotel for Dinner. After having their dinner the Bill Amount was of Rs 2400. So they decided to distribute it into equal amount for each. In the group two friends forget to bring their purses along with them. So later on it has been decided that Rs 100 has to be paid more by the other friends on calculated amount. So total how many friends were there in the Group?

IQ Test Answers

The answers to IQ test questions asked above are given below.

1. 10 miles each according to Pythagoras Theorem.

2. Each Cow has 2 eyes and 4 legs and each bird has 2 eyes and 2 legs. Lets call each eye as x and each leg as y. Also each bird is n and each cow is m so:

3. This is a classic probability puzzle and many puzzles are based on this logic. If the person picks up two socks then there is a possibility of them being different in colour. If he picks up three socks then they are guaranteed red or white. So the minimum number of socks required are three.

4. Let the number be x

105 – x = y x = 105 – y 13x = 105 + y 14 x = 210 x = 15

5. 10 minutes. The total time was one hour and already 50 minutes are over.

6. You can assume that when the fly lands on cyclist 1 they are 50 miles apart. The fly has to travel 50 + x miles at 16 miles/hour. Here x is the additional distance at 10 miles/hour. So the problem is now simplified as

8. When they meet they are both at the same distance away from London.

9. 10 km. Because the dog’s speed is 10 km/h.

10. First, work out how much of the pool gets filled by each tap in one hour. The first tap takes 48 hours to fill the pool, so in one hour it fills 1/48 of the pool. The second tap 1/72. The third tap 1/96. And the fourth tap fills 1/6 of the pool in one hour. We need to add all those fractions together:

1/48 + 1/72 + 1/96 + 1/6 = 61/288

So, in one hour the pool will be 61/288 full and it will be completely full in 288/61 hours = 4 hours 43 minutes and 17 seconds.

11. Tommy was the thief. He was not telling the truth. He stole it.

12. If the guy was from the west, he should answer the truth: I am from the west. If the guy was from the east, he also should tell a lie: I am from the west. The answer will always be: ‘I am from the west’. So we know the tour guide was telling the truth.

13. If the horse is brown. then every one is right. This is not the answer. If the horse is black, then every one is wrong. This is not the answer either. Therefore, the horse is gray. To verify the answer, Allan was right, Brian was right, but Charlie was wrong.

14. Since there is no conflict between what they said, it meant that either they both told a lie or both told the truth. In this case they both told a lie. The answer is the brother is older.

15. The number will be 41312432 or 23421314. Of course these 2 numbers are actually the same, just reverse the direction from one to become another one. The way to solve this is, first all, put down two 4s and reserve 4 spaces between these two 4s. Then you determonw the positions for two 3s. Since you can not put both 3s between 4s, one 3 must be outside of two 4s. After that you just need to try a few cases to find out he answer.

Neither of them had ever met Bernie before. They d never seen a picture or painting of him, nor was he a famous celebrity.

How was this possible?

Alphonso was born as a twin, but he was separated from his twin brother at birth. Bernie is Alphonso s identical twin, which is how Sadie was able to recognize him in the crowd.

This is kind of a cheat, because there are probably other possible explanations. But we can t have everything 🙂

Alphonso was born as a twin, but he was separated from his twin brother at birth. Bernie is Alphonso s identical twin, which is how Sadie was able to recognize him in the crowd.

This is kind of a cheat, because there are probably other possible explanations. But we can t have everything 🙂

There are 125 sheep and 5 dogs in a flock.

How old is the shepherd?

You can t determine the answer.

I debated adding this riddle because it is less of a riddle and more of an illustration of how kids are (or are not) being taught to think for themselves. But after reading how kids feel the need to make up an answer without understanding why, I thought this could be a good reminder for all of us to exercise our critical thinking skills.

You can t determine the answer.

I debated adding this riddle because it is less of a riddle and more of an illustration of how kids are (or are not) being taught to think for themselves. But after reading how kids feel the need to make up an answer without understanding why, I thought this could be a good reminder for all of us to exercise our critical thinking skills.

As a result of temporary magical powers, you have made it to the Wimbledon finals and are playing Roger Federer for all the marbles. However, your powers cannot last the whole match. What score do you want it to be when they disappear, to maximize your chances of hanging on for a win?

It sounds obvious that you should ask to be ahead two sets to love (it takes 3 out of 5 sets to win the men’s), and in the third set, ahead 5-0 in games and 40-love in the sixth game. (Probably you want to be serving, but if your serve is like mine, you might prefer Roger to be serving the sixth game down 0-40 so that you can pray for a double fault.)

Not so fast! These solutions give you essentially 3 chances to get lucky and win, but you can get six chances—with three services by you and three by Roger. You still want to be up two sets to none, but let the game score be 6-6 in the third set and 6-0—in your favor, of course—in the tiebreaker.

Credit goes to Peter Winkler for creating this.

It sounds obvious that you should ask to be ahead two sets to love (it takes 3 out of 5 sets to win the men’s), and in the third set, ahead 5-0 in games and 40-love in the sixth game. (Probably you want to be serving, but if your serve is like mine, you might prefer Roger to be serving the sixth game down 0-40 so that you can pray for a double fault.)

Not so fast! These solutions give you essentially 3 chances to get lucky and win, but you can get six chances—with three services by you and three by Roger. You still want to be up two sets to none, but let the game score be 6-6 in the third set and 6-0—in your favor, of course—in the tiebreaker.

Credit goes to Peter Winkler for creating this.

Zero is nothing, yet when you add zeroes to a number like 1, it becomes 10, 100 or 1,000.

The ancient Greeks did not have a name for zero and did not use a placeholder. They seemed unsure about the status of zero as a number, philosophizing about how nothing could be something. Once zero was added, it allowed for more mathematical understanding.

Zero is nothing, yet when you add zeroes to a number like 1, it becomes 10, 100 or 1,000.

The ancient Greeks did not have a name for zero and did not use a placeholder. They seemed unsure about the status of zero as a number, philosophizing about how nothing could be something. Once zero was added, it allowed for more mathematical understanding.

Concussion (Traumatic Brain Injury)

Concussion

The most common and least serious type of traumatic brain injury is called a concussion. The word comes from the Latin concutere, which means “to shake violently.”

According to the CDC, between 2001 and 2009, an estimated 173,285 people under age 19 were treated in hospital emergency rooms for concussions related to sports and recreation activities. Other causes include car and bicycle accidents, work-related injuries, falls, and fighting.

How can you tell if you have had a concussion? Is it always serious? And what should you do if you have a concussion? Here are answers to some important questions about concussions.

What Is a Concussion?

As seen in countless Saturday morning cartoons, a concussion is most often caused by a sudden direct blow or bump to the head.

The brain is made of soft tissue. It’s cushioned by spinal fluid and encased in the protective shell of the skull. When you sustain a concussion, the impact can jolt your brain. Sometimes, it literally causes it to move around in your head. Traumatic brain injuries can cause bruising, damage to the blood vessels, and injury to the nerves.

The result? Your brain doesn’t function normally. If you’ve suffered a concussion, vision may be disturbed, you may lose equilibrium, or you may fall unconscious. In short, the brain is confused. That’s why Bugs Bunny often saw stars.

Can Children Have Concussions?

Because their heads are disproportionately large compared to the rest of their body, concussions often occur in young children. As kids enter adolescence, they experience rapid height and weight gain. Both are factors that make them more prone to accidents than adults.

If a child has a concussion, an adult should monitor him or her for the first 24 hours. It’s important to watch for behavioral changes. Young children, especially, may not be able to fully communicate what they are feeling, so it is critical to watch them closely. Do not give medications, including aspirin, which may cause bleeding, to a child without consulting a doctor.

What Are the Signs of a Concussion?

Concussions can be tricky to diagnose. Though you may have a visible cut or bruise on your head, you can’t actually see a concussion. Signs may not appear for days or weeks after the injury. Some symptoms last for just seconds; others may linger.

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Concussions are fairly common. Some estimates say a mild brain trauma is sustained every 21 seconds in the U.S. But it’s important to recognize the signs of a concussion so you can take the proper steps to treat the injury.

There are some common physical, mental, and emotional symptoms a person may display following a concussion. Any of these could be a sign of traumatic brain injury:

Are There Different Types of Concussions?

Concussions are graded as mild (grade 1), moderate (grade 2), or severe (grade 3), depending on such factors as loss of consciousness, amnesia, and loss of equilibrium.

In a grade 1 concussion, symptoms last for less than 15 minutes. There is no loss of consciousness.

With a grade 2 concussion, there is no loss of consciousness but symptoms last longer than 15 minutes.

In a grade 3 concussion, the person loses consciousness, sometimes just for a few seconds.

What Should I Do if I Have a Concussion?

The seriousness of a concussion dictates what kind of treatment you should seek. Most people with concussions fully recover with appropriate treatment. But because a concussion can be serious, safeguarding yourself is important. Here are a few steps to take:

Seek medical attention. A health care professional can decide how serious the concussion is and whether you require treatment. If you have suffered a grade 1 or grade 2 concussion, wait until symptoms are gone before returning to normal activities. That could take several minutes, hours, days, or even a week.

If you have sustained a grade 3 concussion, see a doctor immediately for observation and treatment. A doctor will ask how the head injury happened and discuss the symptoms. The doctor may also ask you simple questions such as “Where do you live?,” “What is your name?” or “Who is the president?” The doctor asks these questions to evaluate memory and concentration skills.

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The doctor may test coordination and reflexes, which are both functions of the central nervous system. The doctor may also order a CT scan or an MRI to rule out bleeding or other serious brain injury.

If hospitalization is not required, the doctor will provide instructions for recovery. Aspirin-free medications may be prescribed and you will be advised to take it easy. Experts recommend follow-up medical attention within 24 to 72 hours if symptoms worsen.

Take a break. If your concussion was sustained during athletic activity, stop play and sit it out. Your brain needs time to properly heal, so rest is key. Definitely do not resume play the same day. Athletes and children should be closely monitored by coaches upon resuming play. If you resume play too soon, you risk a greater chance of having a second concussion, which can compound the damage. The American Academy of Neurology has issued guidelines about resuming activities after a concussion.

Guard against repeat concussions. Repeat concussions cause cumulative effects on the brain. Successive concussions can have devastating consequences, including brain swelling, permanent brain damage, long-term disabilities, or even death. Don’t return to normal activities if you still have symptoms. Get a doctor’s clearance so you can return to work or play with confidence.

Can I Prevent a Concussion?

By its very nature, a concussion is unexpected, so it is tough to prevent. But there are several common-sense precautions you can take to lessen the possibility of traumatic brain injury.

Wear protective equipment. Participation in high-contact, high-risk sports such as football, hockey, boxing, and soccer can increase the likelihood of a concussion. Skateboarding, snowboarding, horseback riding, and roller blading are also a threat to your brain’s health. Wearing headgear, padding, and mouth and eye guards can help safeguard against traumatic head injuries. Wearing a bike helmet can lower the risk of traumatic head injury by 85%. Ensure that the equipment is properly fitted, well maintained, and worn consistently.

Drive and ride smart. Always wear a seatbelt, obey posted speed limits, and don’t use drugs or alcohol, because they can impair reaction time.

Don’t fight. Concussions are often sustained during an assault, and more males than females report traumatic head injuries.